The present invention relates generally to interface devices by which users interface with computer systems, and more particularly to computer interface devices that both enable users to provide input to a computer system and convey force feedback from the computer system to the user.
Computer systems in use today typically have a visual display and audio speakers which provide system output and a variety of interface devices that serve system input functions. Common user/computer interface devices include keyboards, mice, trackballs, touch pads, joysticks, tablets, as well as other devices.
Most of these interface devices are specifically engineered to control the position and/or location of a cursor or object on the display. Sensor""s on the interface device convert a user""s manipulation of the device into locative signals that are sent to the computer via either a line cord or xe2x80x9cwirelessxe2x80x9d means. The computer responds to the locative signals by moving the cursor or object.
Because most input devices require manual manipulation by a user, they are ideally suited to also serve as devices for transmitting tactile or haptic feedback to the user. This feedback, commonly referred to as xe2x80x9cforce feedback,xe2x80x9d consists of a physical sensation that is felt by the user manipulating the device. For example, designs have been offered that combine a computer mouse with a vibrating module which generates an output signal in the form of a tactile vibration. Other arrangements provide joysticks or game controllers that, through a connection to a motor, convey movement of some sort that can be sensed by a user.
There are many practical applications for this tactile feedback. They range from computer systems intended for use by the vision or hearing impaired to game systems that enhance a user""s experience through force feedback. It may very well be, however, that tactile output devices will soon become as commonplace as computer keyboards or visual displays.
A variety of tactile output apparatuses, many of which combine a cursor positioning device with a force feedback generator, are offered by the prior art. Probably the simplest arrangement is the mouse/vibrating module combination described above. Though useful, this arrangement suffers from a disadvantage in that the force feedback comes from a vibrating module. The vibration output of the module could cause a user to inadvertently reposition the mouse, thus changing on the display the position or location of the object controlled by the mouse. Furthermore, because the entire device would tend to vibrate when the vibrating module is activated, it would be useless to employ more than one module on the mouse to increase the number of signaling combinations because a user would have difficulty distinguishing which module is generating a particular vibration signal.
Finally, there is a risk that other internal components of the mouse could be damaged over time as a result of the vibration output.
More complex cursor positioning device/tactile output arrangements require armatures, gimbals, linkages, magnets, gear drives, special manipulation surfaces, etc. The complexity of these devices, however, makes them relatively more expensive to manufacture and possibly less reliable. In addition, these arrangements are suitable only in applications where extreme movement of the device (as opposed to discrete, isolated, tactile output) is acceptable.
One disclosure describes a computer mouse with a force feedback control wheel. The control wheel performs cursor control functions and also provides various forms of force feedback to a user such as a resistance to the user""s manipulation of the wheel, rotation of the wheel in both directions, a tendency for the wheel to stop at various points in its rotation, and a vibration motion of the wheel.
As are some of the other arrangements that have been offered, this design is complicated to manufacture. One significant problem is that the device requires a motor or actuator that can reverse directions or do the other things mentioned in the disclosure and also be powerful enough to provide such movement while the wheel is engaged by a finger of the user. Urging of the control wheel by the user in a direction opposite that of the motion provided by the motor or actuator might cause excessive wear (or even break the device under some circumstances). Though the combination of a cursor positioning control wheel with force feedback capability might appeal to some users, a simpler and more reliable design could be preferable for many applications.
The present invention overcomes the above-described limitations of the prior art by disclosing a mechanism for producing a stabilized force feedback. xe2x80x9cStabilizedxe2x80x9d in this context means a tactile output that remains isolated to a particular location without imparting any collateral motion to the device in which it is installed. The mechanism provided by the present invention is suitable for use in combination with virtually any sort of computer interface device (such as a mouse, a keyboard, a touch pad, or a trackball) and is simple in design, cost-effective to manufacture, and reliable in operation.
These goals are accomplished through the use of a non-planar surface that is generally circular in shape and balanced with respect to a rotational axis. An actuator, in response to instructions received from a computer, rotates the non-planar surface at a relatively high rate of revolutions per minute (though even at slower speeds the mechanism will convey tactile output). When a user contacts the rotating non-planar surface the user will detect tactile computer output similar to that output produced by a vibrating module. But because (like an airplane propeller) the non-planar surface is balanced with respect to its rotational axis, the rotating non-planar surface does not generate any collateral vibration or cause any movement of the particular interface device in which the tactile output mechanism is installed.
By isolating the tactile output to the non-planar surface the present invention allows the use of multiple tactile output mechanisms in a single computer input device. An example of this would be a computer mouse that has two or three tactile output mechanisms located in areas where a user""s thumb or fingertips might rest when using the mouse. This type of arrangement cannot be accomplished with vibrating modules since a vibration tactile output signal would tend to vibrate the entire mouse (making it difficult for a user to distinguish which vibrating module is generating the tactile output signal).
Including more than one tactile output mechanism in a single computer input device greatly expands the force feedback signaling possibilities. For instance, each of the various mechanisms could signal a different thing to a user with its tactile output. Or, multiple mechanisms could generate concurrent tactile output signals to indicate something else. In another arrangement the tactile output signal might xe2x80x9cscrollxe2x80x9d through the separate mechanisms to create a third type of force feedback message.
The particular use of the tactile output signal would depend upon software designers. But, because the present invention permits the use of multiple tactile output mechanisms, the force feedback signaling possibilities (and uses) are endless.
These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following specification of the invention and a study of the several figures of the drawings.